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High-Resolution Electron-Impact Study of the Far-Ultraviolet Emission Spectrum of Molecular HydrogenThe emission spectrum of molecular hydrogen produced by electron-impact excitation at 100 eV has been measured in the wavelength range 1140-1690 A. High-resolution, optically thin spectra (delta(lambda) = 0.136 A) of the far-ultraviolet (FUV) Lyman and Werner band systems have been obtained with a newly constructed 3 m spectrometer. Synthetic spectral intensities based on the transition probabilities calculated by Abgrall et al. are in very good agreement with experimentally observed intensities. Previous modeling that utilized Allison & Daigarno band transition probabilities with Hoenl-London factors breaks down when the transition moment has significant J dependence or when ro-vibrational coupling is significant. Ro-vibrational perturbation between upsilon = 14 of the B(sup 1)Sigma(sup +, sub u) state and upsilon = 3 of the C(sup 1)Pi(sub u) state and the rotational dependence of the transition moment in the bands of the Lyman system are examined. Complete high-resolution experimental reference FUV spectra, together with the model synthetic spectra based on the Abgrall transition probabilities, are presented. An improved calibration standard is obtained, and an accurate calibration of the 3 m spectrometer has been achieved.
Document ID
19990018447
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Liu, Xian-Ming (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Ahmed, Syed M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Multari, Rosalie A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
James, Geoffrey K. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Ajello, Joseph M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Date Acquired
August 19, 2013
Publication Date
December 1, 1995
Publication Information
Publication: Astrophysical Journal Supplement Series
Volume: 101
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: NSF ATM 93-20589
Distribution Limits
Public
Copyright
Other